Archeologists have completed their preliminary study of Mael's tomb at Strandhill, Ireland, and the artifacts from the tomb have been moved to the United States. In a Washington museum, an exhibition is being mounted which will highlight the previous (and first) visit of the Taelons (Mael) to Earth.

In the museum, Liam and Sandoval are checking the progress of preparations for the exhibit. They are discussing the eulogy which was delivered at Boone's funeral by Sandoval. Liam tells Sandoval that he found the eulogy enlightening, particularly that part of it which dealt with treason. He reminds Sandoval of the encounter which he and Da'an had with the Jaridian replicant in the tunnels under the Taelon embassy. Liam accuses Sandoval of giving him a weapon to battle the replicant which he (Sandoval) knew would fail and tells Sandoval that a sling shot and a rock would have been more effective against the replicant. Sandoval retaliates by asking Liam why he is still alive if the weapon was defective. Liam tells him that it was "the luck of the Irish".

A sign in the museum indicates that the museum exhibit will open the following day. Sandoval has left the exhibition and Liam, noticing an interesting artifact, walks up to it for a closer look. As he does so, his Sha'karava activates and begins to glow. He places his hand on a section of the exhibit resembling the security panel at the entrance to Resistance Headquarters and a glowing portal opens before him. The surprised Liam steps through the portal and it closes behind him.

On the other side of the portal, Liam looks around and sees that he is still in the museum; everything looks the same, with one notable difference. On the wall of the museum the sign which had previously indicated that the exhibit would open the next day, now says, "Open".

Liam leaves the exhibition and goes to Resistance Headquarters. He steps out of the elevator and looks around in shock. There are dead bodies everywhere; everyone has been shot and is dead. He sees Lili's body lying on the floor and goes over to it to check her pulse; there is an automatic weapon in her hand and she looks as though she went down fighting, but she is dead like everyone else. He flashes back to the scene of the massacre and "sees" Lili firing her automatic weapon at random, spraying the room with gunfire. Jonathan Doors returns fire, hitting Lili and she collapses. As she goes down, Lili fires again, killing Doors. Liam is stunned by what he sees and says out loud, "She killed him". He goes to the computer console. and accesses a online newspaper article on the opening of the museum exhibit. Looking at the dateline, he realizes that he is actually two days in the future. He returns to the museum exhibit and steps back through the portal into the present.

Liam goes to see Augur and tells him what has happened. He tells Augur tat he is the only one he can trust with his experience because he did not see Augur in Resistance Headquarters when the massacre was taking place. Augur is relieved to hear that he was not in the headquarters and was not among the dead, but he does not believe Liam's story and he refuses to believe that Lili could have been the assassin.

On the mother ship Zo'or and Sandoval are discussing Liam and Da'an's encounter with the replicant (First of Its Kind), and Zo'or wonders how Liam was able to destroy the replicant with a weapon which didn't function. Nor can he figure out how Da'an was able to regain his Taelon form and rejoin the Commonality. Taelons have always believed it was impossible to do so. Sandoval asks Zo'or if Da'an (or any Taelon for that matter) is capable of hiding his thought processes from the Commonality. Zo'or explains that the Commonality links all Taelons, but does not allow them to enter into each and every part of each other's minds. Zo'or further says that by returning from the Atavus state and rejoining the Commonality, Da'an has done something that no Taelon has ever done and which only the Kimera were able to do. When Sandoval tells Zo'or that the common denominator between the two events is the presence of Liam Kincaid, Zo'or tells him: "Then I suggest this link be severed, permanently."

Zo'or and Sandoval pay a visit to a research facility where the Taelons have been funding an unusual project. Under the auspices of the Taelons, a research physician, Dr. Barrows, has developed a device capable of transmitting signals which can induce violent insanity in a normal person, turning him or her into a violent psychopath. The transmissions are targeted to a specific subject's brain waves. Zo'or and Sandoval witness a demonstration of the device during which a normally quiet lab technician becomes insane and viciously attacks a coworker. The physician tells them that the psychotic behaviour will continue until the subject is treated. Zo'or is pleased and orders Sandoval to move the project equipment and research personnel to the mother ship.

Da'an and Liam are in Da'an's office, discussing Liam's experience in the museum and whether or not it is possible to change the future. Da'an recounts a Taelon parable (which has a human equivalent) about Death and a rich man's servant who thought he could cheat his fate. He tells Liam that "the future can be changed, but only if fate will allow it". He also tells Liam that Taelons do not tempt fate, which is why they have banned travel in time, the fourth dimension.

Liam falls asleep in his new apartment and has a dream. In his dream he enters Resistance Headquarters armed with a automatic weapon. When the elevator stops, he bursts from it, firing his weapon and mercilessly mowing down everyone in the room. He does not stop until everyone is dead including Lili and Doors. He awakens from the dream in a cold sweat and says, "It's me, I'm the killer."

On the Mother Ship, Dr. Barrows and his team set up their lab equipment and their transmitting device and begin calibrations to permit the device to be used; this time it will not be a test or a demonstration.

In a complete panic, Liam goes to Augur's and recounts his dream. The sceptical Augur tries to reassure Liam by telling him that he was merely having a dream, but Liam is not comforted. He believes that it was a true dream, that the events in it will occur, and that he is the assassin.

At the embassy, Liam asks Da'an to explain the Sha'karava to him, because he needs to learn how to control it. Da'an explains he cannot as the Sha'karava did not originate with the Taelons; they acquired it from the Kimera (the race of Liam's father Ha'gel) when the two races joined together. Liam states that the Sha'karava is more than weapon. Da'an tells him that for the Kimera, the Sha'karava embodied the essence and totality of their race, but that the Taelons could not control the violence that the Sha'karava allowed and created the Commonality to do so. Da'an says that the ability to control the Sha'karava lies within Liam himself. Liam says: "Like controlling the killer inside me?" Da'an bows and says regretfully, "Yes, I'm sorry."

Augur is at the bar in the Flat Planet Café, chatting up a female when Lili appears. Augur had contacted her to arrange a meeting because he is worried about Liam. Lili pretends that she is Augur's wife and the woman leaves. This gives Lili a chance to talk to Augur about Liam's frame of mind. He tells Lili about Liam's journey through the portal and his strange dream. Lili feels that the Taelons are somehow involved in the situation.

The mother ship moves into a position closer to earth as it must be as close as possible for Dr. Barrows' transmissions to be effective. The device is activated and Dr. Barrows tells Zo'or and Sandoval that the subject will become psychotic in about forty-eight hours.

On earth, the mother ship's new position is noted by Jonathan Doors who believes that Da'an has betrayed the location of the Resistance and the mother ship is preparing to attack the Resistance.

Augur asks Holo Lili to scan the mother ship to find out what is going on and discovers the signals being transmitted by Dr. Barrow's device.

At Headquarters, Doors, who is exhibiting pronounced paranoid symptoms, has an argument with Lili, saying that the Resistance has been betrayed by Da'an and they are going to be attacked.. He orders the Resistance members to prepare the headquarters for an assault. When Lili tries to tell Doors about Liam's experience, Doors replies that he told Lili to stay away from Liam and that he (Liam) is to be shot on sight. Lili refuses and Doors hands her a weapon and tells her it is time for her to choose.

Augur has analysed the transmissions from the mother ship and informs Liam that the Taelons are trying to drive someone in the area insane. On instructions from Augur, Liam travels to the mother ship and downloads the information from the ship's database so that Augur can learn exactly who is being targeted by Dr. Barrows' machine. When he does, Augur is shocked to discover who it is. On the way back to earth in his shuttle, Liam accesses the data himself and learns that he is the target.

Back on earth, Liam decides to commit suicide rather than be responsible for killing his friends in the Resistance. He returns to his apartment, writes a letter for Augur to be opened after his death, and leaves it on the windowsill. He seats himself in a chair on the mezzanine level of his apartment and activating his Sha'karava, he places his palms against his forehead. Suddenly Augur bursts into the apartment with the news that Liam is not the target and tries to stop him, but Liam does not respond. Augur tries to stop Liam by grabbing his hands, is hit by a blast from the Sha'karava and is hurled over the railing into the room below. Liam comes to and rushes down the stairs to Augur who appears to be dead. He activates his Sha'karava, putting one hand on Augur's chest (over his heart) and the other hand on Augur's forehead. Augur regains consciousness and tells Liam that in order to create his false identity, he had to use someone else's brainwaves because Liam's weren't entirely human. As a private joke, Augur used the brain waves of Jonathan Doors and it is Doors who is actually being targeted by Dr. Barrows' machine (although they don't know it)..

At Resistance Headquarters, Doors is becoming increasingly paranoid and has sealed off headquarters entirely.

Liam and Augur are unable to contact anyone at headquarters and are forced to go there in person. Augur tells Liam that Lili knows about the situation and will think he is coming to kill everyone. Liam says they will just have to think up something.

On the mother ship, Zo'or and Sandoval are watching Dr. Barrows at work and discussing the fact that Liam will collapse and become insane at any moment. Zo'or tells Sandoval that the present exercise is only the first step and that Da'an will be next, unless Liam kills him in a moment of insanity, saving them the trouble of having to do so.

Liam and Augur manage to enter Resistance headquarters by circumventing security and take the elevator down to headquarters. Liam is still worried, thinking that although he is not the assassin, he may still be the catalyst. When the elevator doors open, Doors begins firing at Liam and Augur, but his gun jams. Liam leaps out of the elevator and fires at Doors with his Sha'karava before Doors can seize another weapon. All eyes and every weapon in headquarters are on Liam. Augur steps in front of Liam and asks everyone not to shoot. He reveals that Doors is actually the target of the Taelons; Liam tells those present that they must restrain and sedate Doors before he awakens or he will kill everyone. Lili hesitates for a moment, but when Doors regains consciousness and lunges at Liam with a weapon, she orders that he be stopped and sedated.

In the embassy, Liam asks Da'an how he can learn to control his Sha'karava. Da'an tells Liam that it is a given that a beast may lurk in the depths of one's soul, and that we all have a dark side, from the most primitive species to the most highly evolved. He tells Liam that he must embrace his dark side and understand it in order to control the Sha'karava and harness its power. Liam asks what he will do if he kills an innocent person along the way and Da'an tells him that if he does, he will simply have to live with it. Referring to the murders Da'an committed in the Atavus state, Liam asks him: "As you have?" and Da'an replies sorrowfully: "As I must."